Looks like moss to me. You'll need to scarify the grass if it is.

The grass blades have a blue tint to them. The blades are also very thick. I know what moss looks like but is there variations of moss? To me its not moss but i could be wrong.

I dont tihnk there is any moss at all ? Looks like you have over treated an area of grass to me? Have you applied anything this year?

just weed and feed like i do every year.

I have a very similar look to my lawn...as does my neighbour...and the huge school field behind our house. I will follow this with interest!

Ah well I should never comment on Qs about grass as we don't have any...

Could it be fusarium patch?

It almost looks like bermudagrass, our best lawn and worst weed, here in the desert--but I would be shocked to find it in the UK!! Maybe a weedy form of bentgrass?

Ive just googled bermudagrass. It does look like bermudagrass but how,what,where and when?

Just looks like weed grass mixed in with lawn grass to me - did you notice it last year as well? Can't suddenly just have appeared... although to be fair, I can't really see it properly, need a close up.

its been around for 2 to 3 years now. it just appeared then grew and grew.

You may have to spot spray with RoundUp, or the like, and replant those spots.

Bamboo if you press control and + or control and - on your key board this picture goes bigger or smaller - thats how I could see it was not moss.

Very difficult to tell from your pics but i guess you have weed grasses growing in your lawn. It also looks like you have a either alot of thatch present and maybe a fungal disease called red thread. A good rake through will reduce thatch. Cutting in different directions can help with coarse weed grasses but best measure unfortunatley is to take out and reseed or returf. A good lawn fetiliser should clear up red thread. Another option is to get lawn treatment company to take a look for you. Most do a free quote and lawn analysis report.